RELATIONSHIP OF ACIDITY-BASICITY OF SALTS OF 3d -METALS WITH THEIR ABILITY FOR FORMATION OF AQUA (AMMIN) COMPLEX COMPOUNDS
The general nature of the relationship between the acid-base properties (electronegativity) of 3d-metal salts and their ability to form aqua and ammine complex compounds (hydrates and ammoniates) has been established. The thermal strength of metal-ligand bonds (H2O, NH3), defined as the enthalpy of...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Odessa I. I. Mechnikov National University
2020-03-01
|
| Series: | Vìsnik Odesʹkogo Nacìonalʹnogo Unìversitetu: Hìmìâ |
| Subjects: | |
| Online Access: | http://heraldchem.onu.edu.ua/article/view/198310 |
| _version_ | 1818565519036383232 |
|---|---|
| author | V. F. Zinchenko V. P. Antonovich V. V. Menchuk |
| author_facet | V. F. Zinchenko V. P. Antonovich V. V. Menchuk |
| author_sort | V. F. Zinchenko |
| collection | DOAJ |
| description | The general nature of the relationship between the acid-base properties (electronegativity) of 3d-metal salts and their ability to form aqua and ammine complex compounds (hydrates and ammoniates) has been established. The thermal strength of metal-ligand bonds (H2O, NH3), defined as the enthalpy of formation of a complex compound per bond depends on many factors: the coordination number of the central metal ion, the nature of the metal, anion, and ligand. An increase in the electronegativity of compounds in the series nitrates – chlorides – sulfates of 3d-metals (Mn2+, Fe2+, Co2+, Ni2+, Cu2+, Zn2+, as well as its decrease when H2O is replaced by NH3 (with the same coordination number) results in an increase in strength by a decrease in enthalpy per 1 metal-ligand bond of complex compounds. In turn, the change in electronegativity is due to the size-charge parameters (metal ionic radius, counter ion charge) of the cations and anions that make up the compounds. There is a correspondence in the change in the total enthalpy of formation of aqua complex compounds (crystalline hydrates) and their diluted solutions. An explanation of this relationship is proposed, based on the recognition of the important role of the chemical component in the process of dissolution of compounds in water. Similar, albeit in a less pronounced form, processes take place in 3d-metal hydroxides, which have mainly basic properties. When water molecules are replaced by ammonia molecules, the solubility of hydroxides in the series Mn(OH)2, Fe(OH)2, Co(OH)2, Ni(OH)2, Cu(OH)2, Zn(OH)2 significantly increases, indicating, together with a change in color, the strengthening of complex compounds. Found regularities make it possible to use the electronegativity parameter to predict and control complexation in other groups of compounds (salts, hydroxides, and molecular ligands). |
| first_indexed | 2024-12-14T01:42:20Z |
| format | Article |
| id | doaj.art-66b10d3f36ea49ee9105f9a4f292a73a |
| institution | Directory Open Access Journal |
| issn | 2304-0947 2414-5963 |
| language | English |
| last_indexed | 2024-12-14T01:42:20Z |
| publishDate | 2020-03-01 |
| publisher | Odessa I. I. Mechnikov National University |
| record_format | Article |
| series | Vìsnik Odesʹkogo Nacìonalʹnogo Unìversitetu: Hìmìâ |
| spelling | doaj.art-66b10d3f36ea49ee9105f9a4f292a73a2022-12-21T23:21:41ZengOdessa I. I. Mechnikov National UniversityVìsnik Odesʹkogo Nacìonalʹnogo Unìversitetu: Hìmìâ2304-09472414-59632020-03-01251(73)142310.18524/2304-0947.2020.1(73).198310198310RELATIONSHIP OF ACIDITY-BASICITY OF SALTS OF 3d -METALS WITH THEIR ABILITY FOR FORMATION OF AQUA (AMMIN) COMPLEX COMPOUNDSV. F. Zinchenko0V. P. Antonovich1V. V. Menchuk2Фізико-хімічний інститут ім. О.В. Богатського НАН УкраїниФізико-хімічний інститут ім. О.В. Богатського НАН УкраїниОдеський національний університет імені І.І. МечниковаThe general nature of the relationship between the acid-base properties (electronegativity) of 3d-metal salts and their ability to form aqua and ammine complex compounds (hydrates and ammoniates) has been established. The thermal strength of metal-ligand bonds (H2O, NH3), defined as the enthalpy of formation of a complex compound per bond depends on many factors: the coordination number of the central metal ion, the nature of the metal, anion, and ligand. An increase in the electronegativity of compounds in the series nitrates – chlorides – sulfates of 3d-metals (Mn2+, Fe2+, Co2+, Ni2+, Cu2+, Zn2+, as well as its decrease when H2O is replaced by NH3 (with the same coordination number) results in an increase in strength by a decrease in enthalpy per 1 metal-ligand bond of complex compounds. In turn, the change in electronegativity is due to the size-charge parameters (metal ionic radius, counter ion charge) of the cations and anions that make up the compounds. There is a correspondence in the change in the total enthalpy of formation of aqua complex compounds (crystalline hydrates) and their diluted solutions. An explanation of this relationship is proposed, based on the recognition of the important role of the chemical component in the process of dissolution of compounds in water. Similar, albeit in a less pronounced form, processes take place in 3d-metal hydroxides, which have mainly basic properties. When water molecules are replaced by ammonia molecules, the solubility of hydroxides in the series Mn(OH)2, Fe(OH)2, Co(OH)2, Ni(OH)2, Cu(OH)2, Zn(OH)2 significantly increases, indicating, together with a change in color, the strengthening of complex compounds. Found regularities make it possible to use the electronegativity parameter to predict and control complexation in other groups of compounds (salts, hydroxides, and molecular ligands).http://heraldchem.onu.edu.ua/article/view/198310кислотність-основністьелектронегативністьсолі 3d-металіваква- та амін-комплексигідроксиди |
| spellingShingle | V. F. Zinchenko V. P. Antonovich V. V. Menchuk RELATIONSHIP OF ACIDITY-BASICITY OF SALTS OF 3d -METALS WITH THEIR ABILITY FOR FORMATION OF AQUA (AMMIN) COMPLEX COMPOUNDS Vìsnik Odesʹkogo Nacìonalʹnogo Unìversitetu: Hìmìâ кислотність-основність електронегативність солі 3d-металів аква- та амін-комплекси гідроксиди |
| title | RELATIONSHIP OF ACIDITY-BASICITY OF SALTS OF 3d -METALS WITH THEIR ABILITY FOR FORMATION OF AQUA (AMMIN) COMPLEX COMPOUNDS |
| title_full | RELATIONSHIP OF ACIDITY-BASICITY OF SALTS OF 3d -METALS WITH THEIR ABILITY FOR FORMATION OF AQUA (AMMIN) COMPLEX COMPOUNDS |
| title_fullStr | RELATIONSHIP OF ACIDITY-BASICITY OF SALTS OF 3d -METALS WITH THEIR ABILITY FOR FORMATION OF AQUA (AMMIN) COMPLEX COMPOUNDS |
| title_full_unstemmed | RELATIONSHIP OF ACIDITY-BASICITY OF SALTS OF 3d -METALS WITH THEIR ABILITY FOR FORMATION OF AQUA (AMMIN) COMPLEX COMPOUNDS |
| title_short | RELATIONSHIP OF ACIDITY-BASICITY OF SALTS OF 3d -METALS WITH THEIR ABILITY FOR FORMATION OF AQUA (AMMIN) COMPLEX COMPOUNDS |
| title_sort | relationship of acidity basicity of salts of 3d metals with their ability for formation of aqua ammin complex compounds |
| topic | кислотність-основність електронегативність солі 3d-металів аква- та амін-комплекси гідроксиди |
| url | http://heraldchem.onu.edu.ua/article/view/198310 |
| work_keys_str_mv | AT vfzinchenko relationshipofaciditybasicityofsaltsof3dmetalswiththeirabilityforformationofaquaammincomplexcompounds AT vpantonovich relationshipofaciditybasicityofsaltsof3dmetalswiththeirabilityforformationofaquaammincomplexcompounds AT vvmenchuk relationshipofaciditybasicityofsaltsof3dmetalswiththeirabilityforformationofaquaammincomplexcompounds |